Haemodynamic advantages of a combined inotropic/venodilator regimen over inotropic monotherapy in acute heart failure.

The haemodynamic influence of positive inotropic therapy with dobutamine, both alone and when combined with isosorbide dinitrate, was evaluated in 10 consecutive patients admitted to Coronary Care with acute left ventricular failure (pulmonary artery occluded pressure greater than 20 mm Hg) complicating myocardial infarction. Dobutamine increased systemic arterial blood pressure and heart rate without reduction in the left heart filling pressure; cardiac index (+0.9 L/min/m2; p less than 0.01) was substantially increased. Thus, consequent on these effects, dobutamine could increase myocardial oxygen requirements. The addition of intravenous isosorbide dinitrate reduced systemic arterial pressure and left heart filling pressure; the augmented cardiac index following therapy with dobutamine alone was maintained. Combined dobutamine/nitrate therapy, therefore, appeared haemodynamically superior to dobutamine monotherapy, in that it improved cardiac stroke volume at a normalised left ventricular filling pressure. These data suggest that combined dobutamine/nitrate therapy may prove useful as an adjunct to the treatment of normotensive heart failure complicating acute myocardial infarction.